1. Field of the Invention
The invention relates to a combing cylinder for a combing machine. Specifically, this invention relates to a combing cylinder having a wing-shaped combing segment which acts to pull fibers towards the comb.
2. Description of the Prior Art
Combing machines are used for combing out fibers such as in making high quality yarns. In the course of such combing, the individual fibers of a group or fringe of fibers are held fast between a nipper and a cushion plate which form pincers aligned parallel with one another. In the combing operation, the fibers are cleansed of contaminations and short or tangled fibers are removed.
The active part of the combing machine is a combing segment seated on the body of the combing cylinder. Such a segment has a number of rows of teeth or needles arranged on its outside surface. The teeth or needles of the combing segment engage and comb the fiber fringe fed to it by the pair of pincers. Such teeth or needles can be fully effective only if they act on the group of fibers before the combing period starts, i.e., from the moment at which the leading edge or beginning of the combing segment seated on the rotating cylinder arrives at the meeting point of the pincers. This condition is generally not met, especially if the combing cylinder is rotated at high speeds (RPM). This is because the front-most needles or teeth engage the fiber fringe only after they have moved away from the pincers.
In order to permit the fibers to be acted on at an earlier point in time, it has been proposed by U.S. Pat. No. 3,922,757, which issued to Horiuchi et al, to reduce the gap or clearance between the lower part of the pincers and the beginning of the combing segment by providing a specially shaped combing segment. Specifically, Horiuchi teaches that the combing segment is mounted on the combing cylinder at a greater distance from the axis of rotation at the starting point of the combing segment than the distance to the rotational axis at the end of the combing segment. In this way, the leading edge of the combing segment is brought much closer to the meeting point of the pincers. However, it has been found, especially with high-speed combing machines, that the group of fibers nevertheless is still not acted upon at the start of the combing period. Thus, the combing segment is not effective over the entire combing period.